Control system for gas turbine engine

ABSTRACT

A control system is disclosed for a vehicle gas turbine engine having a power turbine driving a power transmission of a motor vehicle on which the gas turbine engine is mounted, an adjustable nozzle which is positioned relative to the power turbine, and a combustor, wherein a flow of fuel to the combustor, an angular position of the adjustable nozzle relative to the power turbine and a fluid pressure controlling a gear train control system of the power transmission are concurrently regulated electrically in accordance with a variation of the selected position and accordingly of the opening degree of an accelerator pedal.

llite State uloota et al.

atent 11 1 1 Sept. 11, 1973 CONTROL SYSTEM FOR GAS TURBINE ENGINElnventors: Seishi Kubota, Yokosuka; Takashi Kunugi, Yokohama; TetsuoKatsume, Yokosuka, all of Japan Assignee: Nissan Motor Company, Limited,

Yokohama City, Japan Filed: July 23, 1971 Appl. No.2 165,048

Primary ExaminerCharles J. Myhre Assistant Examiner-Thomas C. PerryAtt0rneyRobert E. Burns et al.

, [57] ABSTRACT Foreign pp ity Data A control system is disclosed for avehicle gas turbine Sept, 17, 1970 Japan 45/81509 engine having a powert r n dri ing a power transmission of a motor vehicle on which the gasturbine en- [52] U.S. Cl 74/843, 60/39.17, 60/3925, g is mounted, anadjustable nozzle which is p i- 74/866 74/D1(, 5 tioned relative to thepower turbine, and a combustor, [51] Int. Cl. B60k 21/00, F02C 9/02wherein a flow of fuel to the combustor, an a g a p [58] Field of Search74/866, 843, 861, Sitiofl 0f the ju l n ZZle relative to the power tur-74/DIG, 5; 60/3917 3925 bine and a fluid pressure controlling a geartrain control system of the power transmission are concurrently [56] IReferences Cited regulated electrically in accordance with a variationof UNITED STATES PATENTS the selected position and accordingly of theopening 3,523,423 8/1970 Young 60 3916 R x degree of accelemtor pedal3,439,564 4/1969 Scholl et al. 74/866 5 Claims, 6 Drawing Figures AC C EL. DE TEC T. 25 FLOW NOZZLE 26 28 CONTROL CONTROL 27 22 1 LINKAG 2OCONTROL SELECTOR 2| Ll V Pmmimr i 3.757.610

sum 3 M5 a L F Flg. 3 (a) g 3 O ACCEL. PEDAL OPENING, D

LU F lg. 3 (b) g 4 9 VOLTAGE, Vd

T LLI F lg. 3 (c) 2 VOLTAGE, Vd

0 LL]-- F lg. 3 (d) g 5 O VOLTAGE, Vd

CONTROL SYSTEM FOR GAS TURBINE ENGINE This invention relates to a gasturbine engine and, more particularly to a control system of the gasturbine engine.

The gas turbine engine to which this invention is directed is used as aprime mover of a motor vehicle and operates in association with anaccelerator pedal and an automatic power transmission system. Such gasturbine engine per se is well known in the art and includes a combustor,a power turbine, an adjustable nozzle positioned relative to the powerturbine and a power sensing linkage which is associated with the powertransmission system. The power sensing linkage is adapted to regulatethe fluid pressure in a hydraulic control circuit of the powertransmission.

The flow of the fuel to the combustor, the angle at which the adjustablenozzle is positioned relative to the power turbine and the movement ofthe power sensing linkage are commonly regulated in terms of a selectedposition of the accelerator pedal by the aid of mechanical. controlarrangements or hydraulic or pneumatic control systems or bycombinations thereof. Regulation of these mutually delicately relatedoperational variables is not fully acceptable for exactly andsensitively following the varying positions of the accelerator pedal.This invention thus contemplates provision of a solution to this problemand an important object of the invention is to provide an improvedcontrol system adapted to reliably and minutely regulate the above notedoperational variables in accordance with the se lected positions of theaccelerator pedal so that the gas turbine engine operates at all timesin those conditions which are optimum for the accelerator positions.

In the drawings:

FIG. 1 is a diagrammatic view showing an overall construction of a gasturbine engine into which the control system according to this inventionis incorporated;

FIG. 2 is a block diagram illustrating a preferred embodiment of thecontrol system; and

FIGS. 3a, 3b, 3c and 3d are views showing waveforms of signal voltagesused in the control system shown in FIG. 2.

Reference is first made to FIG. 1, in which the gas turbine engine isdiagrammatically shown to include power and compressor turbines 11 and12, respectively. The power turbine 11 is connected to a drive shaft 13of an automatic power transmission 14 through a shaft 15 and reductiongears 16 and 17. The compressor turbine 12, on the other hand, isconnected to a compressor 18 through a shaft 19. I

An-adjustable nozzle 20 is positioned relative to the power andcompressor turbines l1 and 12, respectively. The angle of the adjustablenozzle 20 with respect to the turbines l1 and 12 can be varied so as tochange the relative rotational speeds of the two turbines. A combustor21 burns a mixture of air and fuel to drive the power and compressorturbines 11 and 12, respectively.

The power transmission 14 includes a gear train (not shown) and ahydraulic control system 140 for selecting gear ratios in the geartrain. The gear train control system 14a is connected to and operated bya vehicle speed selector 22 through a linkage 23 whereby a gear ratiocorresponding to a vehicle speed manually selected in the selector 22 isestablished in the power transmission 14. The gear train control system14a is also connected to a power sensing linkage 24 through itshydraulic control unit (not shown) so as to control the hydraulic geartrain control system 14a in relation to the movement of an acceleratorpedal (not shown).

The gas turbine engine shown in FIG. 1 per se is well known in the artand, as such, no detailed discussion of the construction and'operationthereof is herein incorporated. I

The flow of the mixture to the combustor 21, the angle of the adjustablenozzle 20 relative to the turbines 11 and 12,and the relative positionof the power sensing linkage 24 are all regulated in accordance with theselected position of the accelerator pedal so that the gas turbineengine can operate in conditions following the accelerator pedalpositions.

To achieve this purpose, thecombustor 21, adjustable nozzle 20 and powersensing linkage 24 are operatively connected to and controlled byrespective control means 25, 26 and 27. These means 25, 26 and 27 areelectrically connected to a common accelerator pedal position detector28 detecting a selected position of the accelerator pedal duringoperation. The control means 25 is adapted to regulate the flow of thefuel to the combustor 21 and the control means 26 is adapted to regulatethe angle at which the adjustable nozzle 20 is positioned relative tothe turbines 11 and 12, whereby the relative rotational speeds of theturbines 11 and 12 are regulated in accordance with the selectedaccelerator pedal position. The control means 27, on the other hand, isadapted to regulate the movement of the power sensing linkage 24,controlling the hydraulic gear train control system 14a to shift thegear ratios to meet the accelerator pedal requirement. This controlmeans 27 is usually located in an automatic power transmission so as todetermine the driving power required for the selected position of theaccelerator pedal (or otherwise the selected angular position of acarburetor throttle valve) for regulating the movement of the powersensing linkage. The movement of the power sensing linkage istransferred to the hydraulic control unit of the transmission thereby toestablish a gear ratio appropriate for the detected accelerator pedalposition.

A preferred electrical arrangement of the control system which is thusmade up of the fuel flow control means 25, the adjustable nozzle controlmeans 26, the power sensing linkage control means 27 and the acceleratorpedal position detector 28 is illustrated in FIG.

Referring to FIG. 2, the accelerator pedal position detector 28 is shownto comprise a rheostat 28a having a sliding arm 28b which is moved inrelation to the movement of the accelerator pedal. The detector 28 isconnected to a source 29 of electric power and produces a signal voltageV,, which is substantially proportional to the opening degree D of theaccelerator pedal, as indicated in (a) of FIG. 3. The signal voltage Vdelivered from the accelerator position detector 28 is distributed tothe fuel flow control means 25, adjustable nozzle control means 26 andpower sensing linkage control means 27. These control means 25, 26 and27 have respective function generators 25a, 26a and 27a which areconstructed to convert the input voltage V,, into respective signalvoltages V,, V, and V,, with different waveforms and which comprisepredetermined operating programs. The waveforms of the signal voltagesproduced by the function generators 25a,

26a and 27a are predetermined so as to meet the respective operationrequirements of the combustor 21, adjustable nozzle and power sensinglinkage 24 (FIG. 1), examples of such waveforms being illustrated in(b), (c) and (d) of FIG. 3.

The function generators a, 26a and 27a are connected respectively toamplifiers 25b, 26b and 27b whereby the output-voltages V,, V,, and V,of the function generators are amplified.

The amplifier 25b of the fuel flow control means 25 is connected throughservo means such as a servo motor 25c to a fuel flow regulator valve 25dregulating the flow of the fuel to the combustor 21 in accordance withthe predetermined characteristics of the voltage V, produced by thefunction generator 25a. The amplifier 26b of the adjustable nozzlecontrol means 26 is connected through servo means such as a servocylinder 26c to a regulator 26d whereby the angular position of theadjustable nozzle 20 is varied relative to the power and compressorturbines l1 and 12, respectively, to meet the characteristics of thevoltage V, produced by the function generator 26a. The amplifier 27b ofthe power sensing linkage control means 27, on the other hand, isconnected through servo means such as a servo cylinder 27c to a linkageregulator 27d adapted to regulate the displacement of the power sensinglinkage 24(FIG. 1) so as to control the hydraulic gear train controlunit 14a.

The outputs from the flow regulator valve 25d, the nozzle positioner 26dand the linkage regulator 27d may preferably be converted into signalvoltages and fed back to summing points located ahead of the associatedamplifiers 25b, 26b and 2712, respectively, through a fuel flow sensor25c, a nozzle position sensor 266: and a linkage displacement sensor27c, respectively.

The flow of the fuel to the combustor 21, angular position of theadjustable nozzle 20 and movement of the power sensing linkage 24 arethus regulated in accordance with the selected opening degree of theaccelerator pedal.

The accelerator pedal position detector 28 and the function generators25a, 26a and 27a may preferably use electronic elements so as to provideincreased response, to facilitate determination, re-adjustment and- /ormodification of the characteristics of the signal voltages to be used inthe control system and to save the accelerator pedal from a mechanicalload which may otherwise add to the pressing effort by a vehicle driver.

What is claimed is:

1. In a motor vehicle having a power transmission which includes a geartrain control system controlled by a power sensing linkage, anautomotive gas turbine engine having a power turbine connected to drivesaid power transmission, a compressor turbine, an adjustable nozzleadjustably positionable relative to said power and compressor turbines,a combustor and a depressible accelerator pedal, a control systemcomprising: detecting means connected to said accelerator pedal forproducting a signal voltage substantially proportional to the degree ofdepression of said accelerator pedal, said detecting means comprising anelectric circuit having a constant voltage source and a rheostat; fuelflow control means responsive to said signal voltage for regulating theflow of fuel to said combustor; nozzle control means responsive to saidsignal voltage for regulating the angle at which said adjustable nozzleis positioned relative to said power and compressor turbines; and powersensing linkage control means connected to said power sensing linkageand responsive to said signal voltage for regulating the displacement ofsaid power sensing linkage for controlling said gear train controlsystem.

2. A control system according to claim 1, wherein said detecting meansincludes a sliding arm slidable on said rheostat and connected to saidaccelerator pedal.

3. A control system according to claim 1, wherein each of said fuelflow, nozzle and power sensing linkage control means comprises afunction generator connected to said detecting means and operative toconvert said signal voltage into another signal voltage having apredetermined operating characteristic determined in relation to itsassociated control means, an amplifier connected to said functiongenerator, a servo means connected to said amplifier, a regulatorconnected to said servo means for regulating each of said flow, angleand displacement by a signal supplied from said servo means, and meansfor sensing the output of said regulator and feeding back a signalrepresenting the output to said amplifier.

4. In a motor vehicle having a power turbine connected to a variablespeed transmission, an adjustable nozzle adjustably positionablerelative to said power turbine, a combustor for receiving therein acombustible fuel mixture for burning same and delivering the combustionproducts to said adjustable nozzle and a variably positionableaccelerator pedal operated during use of the motor vehicle by a motorvehicle operator, a control system for controlling the motor vehicle independence upon the position of said accelerator pedal comprising:detecting means for detecting the position of said accelerator pedal andproducting a corresponding output signal independently of the motorvehicle speed; nozzle control means responsive to said output signal forcontrolling the flow rate of fuel to said combustor in accordance with apredetermined program; and transmission control means responsive to saidoutput signal for controlling the speed of said transmission inaccordance with a predetermined program.

5. A motor vehicle according to claim 4; wherein said detecting meanscomprises a constant voltage source; and a rheostat connected to saidconstant voltage source, said rheostat having a resistor connected inseries with said constant voltage source and a slidable contact armconnected to said accelerator pedal for movement therewith and slidablealong said resistor to produce a variable output signal in dependenceupon the position of said accelerator pedal.

* i t I t

1. In a motor vehicle having a power transmission which includes a geartrain control system controlled by a power sensing linkage, anautomotive gas turbine engine having a power turbine connected to drivesaid power transmission, a compressor turbine, an adjustable nozzleadjustably positionable relative to said power and compressor turbines,a combustor and a depressible accelerator pedal, a control systemcomprising: detecting means connected to said accelerator pedal forproducting a signal voltage substantially proportional to the degree ofdepression of said accelerator pedal, said detecting means comprising anelectric circuit having a constant voltage source and a rheostat; fuelflow control means responsive to said signal voltage for regulating theflow of fuel to said combustor; nozzle control means responsive to saidsignal voltage for regulating the angle at which said adjusTable nozzleis positioned relative to said power and compressor turbines; and powersensing linkage control means connected to said power sensing linkageand responsive to said signal voltage for regulating the displacement ofsaid power sensing linkage for controlling said gear train controlsystem.
 2. A control system according to claim 1, wherein said detectingmeans includes a sliding arm slidable on said rheostat and connected tosaid accelerator pedal.
 3. A control system according to claim 1,wherein each of said fuel flow, nozzle and power sensing linkage controlmeans comprises a function generator connected to said detecting meansand operative to convert said signal voltage into another signal voltagehaving a predetermined operating characteristic determined in relationto its associated control means, an amplifier connected to said functiongenerator, a servo means connected to said amplifier, a regulatorconnected to said servo means for regulating each of said flow, angleand displacement by a signal supplied from said servo means, and meansfor sensing the output of said regulator and feeding back a signalrepresenting the output to said amplifier.
 4. In a motor vehicle havinga power turbine connected to a variable speed transmission, anadjustable nozzle adjustably positionable relative to said powerturbine, a combustor for receiving therein a combustible fuel mixturefor burning same and delivering the combustion products to saidadjustable nozzle and a variably positionable accelerator pedal operatedduring use of the motor vehicle by a motor vehicle operator, a controlsystem for controlling the motor vehicle in dependence upon the positionof said accelerator pedal comprising: detecting means for detecting theposition of said accelerator pedal and producting a corresponding outputsignal independently of the motor vehicle speed; nozzle control meansresponsive to said output signal for controlling the flow rate of fuelto said combustor in accordance with a predetermined program; andtransmission control means responsive to said output signal forcontrolling the speed of said transmission in accordance with apredetermined program.
 5. A motor vehicle according to claim 4; whereinsaid detecting means comprises a constant voltage source; and a rheostatconnected to said constant voltage source, said rheostat having aresistor connected in series with said constant voltage source and aslidable contact arm connected to said accelerator pedal for movementtherewith and slidable along said resistor to produce a variable outputsignal in dependence upon the position of said accelerator pedal.